The electronic products nowadays are usually provided with touch display panels. The capacitive touch display panel is the most common type of touch display panel.
The capacitive touch display panel operates based on current induction caused by a human body. Usually, the capacitive touch display panel is a four-layer composite glass screen. When a user touch a surface of the capacitive touch display panel with a finger, a coupling capacitor is generated between the user and the surface of the capacitive touch display panel due to electrical field of human body. Such capacitor may be deemed as a conductor for a high frequency current. Small current may flow into the finger at a touch point where the finger touches the surface of the capacitive touch display panel. The small current may flow out of the capacitive touch display panel from electrodes at four corners of the capacitive touch display panel. Each of the four currents flowing through the electrodes at the four corners respectively is proportional to a distance from the finger to the corner. A controller may determine a location of the touch point by calculating proportional relationship among the four currents accurately.
Force touch is a touch sensing technique applied to liquid crystal display device, with which the display device may sense the value of any force applied by the user to the screen; hence, more kinds of touch operation can be achieved.
The touch screen in related art already has mature structure, and the present disclosure intends to achieve force touch function by making minor changes to the touch screen in related art.